Animal feed and production method thereof

ABSTRACT

Animal feed is obtained by mixing a grain material and/or a fiber material with at least one industrial waste selected from the group consisting of fish-broth effluents, fish viscera, animal wastes, and distillatory effluents, to form a mixture. Subsequently, koji mold is added to the mixture, then allowed to undergo fermentation, and then dried to form the animal feed. A method for producing animal feed comprises the steps of: mixing a grain material and/or a fiber material with at least one industrial waste selected from the group consisting of fish-broth effluents, fish viscera, animal wastes, and distillatory effluents to form a mixture, wherein the water content of the mixture is 45 wt % or less; adding koji mold to the mixture to cause fermentation; and drying the mixture by utilizing heat generated by the fermentation caused by the koji mold and, if necessary, by driving a current of air upon the mixture.

TECHNICAL FIELD

The present invention relates to animal feeds and production methodsthereof. More particularly, the present invention relates to the animalfeeds obtainable by fermenting a mixture of grains and/or fibermaterials and wastes containing protein of animal origin, such as, thoseoriginating from fisheries, livestock industries and food industries,using koji mold, and production methods thereof. The present inventionfurther relates to the use of koji mold in the production of animalfeeds.

BACKGROUND ART

Most industrial wastes are discarded, these including industrialeffluents produced in the production process of foods such as driedskipjacks, fish cakes (fish broth), animal waste produced in livestockindustries, or distillatory effluents resulting from the distillationprocess in the production of liquors.

Only a small proportion of these industrial wastes which are abundant inorganic ingredients have been utilized as efficient soil fertilizersalthough it is preferred in view of recycling.

One reason is that the wastes are bulky due to its substantial watercontent which makes it difficult to stock and transport the wastes.Their tendency to rot quickly is another reason which makes storagedifficult. Accordingly, these waste products have been discarded withoutany effective uses, causing environmental problems such as pollution ofthe soil, groundwater, river and sea.

DISCLOSURE OF INVENTION

The present invention addresses the above-mentioned problems. It is anobject of the present invention to effectively utilize wastes. It isanother object of the present invention to provide a nutritious animalfeed by fermenting a crude mixture containing the above-describedindustrial wastes using koji mold, in which process heat generated byfermentation is utilized to dehydrate the mixture, resulting in a lesscostly process. Yet another object of the present invention is toprovide a method for producing such animal feed having an excellentshelf life. The method comprises controlling the water content of themixture containing the above-described industrial wastes by making useof fermentation heat to dry the mixture.

In the first aspect, the present invention provides animal feed withenhanced digestiveness comprising koji mold and digestive enzymesproduced thereby.

In the second aspect, the present invention provides animal feedproduced by a process in which a grain material and/or a fiber materialis mixed with at least one industrial waste selected from the groupconsisting of fish-broth effluents, fish viscera, animal wastes, anddistillatory effluents, to form a mixture. Koji mold is then added tothe mixture. The mixture is allowed to undergo fermentation and isdried, which completes the animal feed.

The present invention, which utilizes at least one industrial wasteselected from the group consisting of fish-broth effluents, fishviscera, animal wastes, and distillatory effluents, can make effectiveuse of the industrial wastes that would otherwise have been discarded.Amino acids that are contained in the above-described industrial wastesand that are useful in making the animal feed nutritious are efficientlyrecovered. Further, when fish broth or fish viscera are used,unsaturated fatty acids with low melting points that have been found tobe an effective growth promoter can be efficiently recycled.

Thermophilic fungi have been typically used to process the wastes into afertilizer. In such a case, most of the organic substances present inthe processed matter are discomposed into carbon dioxide and water andare released into the atmosphere. In contrast, koji mold used in thepresent invention can resynthesize most of the organic substances intohigh quality fungal proteins although some parts are still converted tocarbon dioxide and water through the fermentation process. Therefore, anadvantage of the present invention is that useful substances aregenerated through the processing of organic waste matter, as comparedwith the conventional waste product processing in which organic wastesare mostly decomposed.

Also, due to the activity of koji mold, various enzymes such as amylasesand proteases are abundantly accumulated in the animal feed of thepresent invention. These enzymes significantly facilitate digestion inthe animals fed with the animal feed.

Further, kojic acid produced by koji mold is renowned as ananti-oxidant. Thus, the animal feed of the present invention enhancesthe inherent healing ability of animals fed with the animal feed of thepresent invention.

In one embodiment, the mixing ratio of the grain material and/or thefiber material to the industrial waste is preferably from 1:0.5 to 1:2by weight. The preferred amount of the koji mold to be added is in therange of 0.05 wt % to 0.2 wt % with respect to the weight of themixture. The efficiency of fermentation is maximized and theabove-described advantages of the present invention become mostsignificant by employing these mixing ratios.

Preferably, the water content of the animal feed after fermentation andthe drying is 30 wt % or less.

In a third aspect of the present invention, a method for producinganimal feed is provided. The method comprises the following steps:mixing a grain material and/or a fiber material with at least oneindustrial waste selected from the group consisting of fish-brotheffluents, fish viscera, animal wastes, and distillatory effluents toform a mixture with the water content of 45 wt % or less; adding kojimold to the mixture to cause fermentation; and drying the mixture byutilizing heat generated by the fermentation caused by the koji moldand, if necessary, by driving a current of air upon the mixture.

The method of the present invention is advantageous in that such enzymesas amylases and proteases are produced, which enables the production ofanimal feed with high digestibility. The amount of enzymes, especiallyproteases, is nearly doubled as compared to conventional animal feeds,due to the protein-rich materials used.

The above-described fermentation and drying steps of the presentinvention may comprise a plurality of steps; that is, the drying stepmay preferably comprise mixing into the mixture an additional volume ofat least one industrial waste when the water content of the mixture isreduced to 35 wt % or less. This makes a mixture having a water contentin the range of 40 wt % to 45 wt %. The industrial waste is selectedfrom the group consisting of fish-broth effluent, fish viscera, animalwaste, and distillatory effluent. The mixture is allowed to continuewith fermentation and drying to form the animal feed with a watercontent of 30 wt % or less.

An additional volume of at least one industrial effluent may also beadded during the drying step when the water content of the mixture isreduced to 35 wt % or less, to form a mixture having a water content inthe range of 40 wt % to 45 wt %. The industrial waste is selected fromthe group consisting of fish-broth effluents, fish viscera, animalwastes, and distillatory effluents. The mixture is allowed to continuewith fermentation and drying until the water content is reduced to 35 wt% or less. The mixture is then mixed with a further volume of at leastone industrial waste selected from the group consisting of fish-brotheffluents, fish viscera, animal wastes, and distillatory effluents, toform a mixture having a water content in the range of 40 wt % to 45 wt%. The resulting mixture is allowed to continue with fermentation anddrying to form an animal feed with a water content of 30 wt % or less.

The efficiency of fermentation is maximized and the above-describedadvantages of the present invention become most significant by employingthese mixing ratios in the above-described multiple steps.

In the fourth aspect, the present invention provides a novel use of kojimold in the production of animal feed with enhanced digestivenesswherein koji mold is mixed with crude materials and laid forfermentation to produce digestive enzymes.

MODES FOR CARRYING OUT THE INVENTION

The preferred embodiments of the present invention will now be describedin detail hereinafter.

Grain materials for use in the present invention include wheat, rice,corn, kaoliang, millet grain, wheat bran, rice bran, corn starch andrice flour.

Fiber materials for use in the present invention include rice bran,wheat bran, tofu refuse, strained lees of fruits, rice hull, andsawdust.

The grain materials and fiber materials described above may be used inthe present invention either independently or in combination.

Industrial wastes for use in the present invention include at least oneselected from the group consisting of fish broth, fish viscera, animalwaste, and distillatory effluent resulting from the distillation ofliquors. Components of the wastes are selected as appropriate dependingon the purpose and may comprise a single component or a mixture ofcomponents.

Fish broths for use in the present invention includes the water used forboiling skipjack fish in manufacturing dried skipjack products, andthose produced while manufacturing other fishery products such as fishcakes and canned fish products.

Fish viscera for use in the present invention include any parts of fishand not limited to internal organs, that have conventionally beenremoved from whole fish to be discarded in manufacturing fisheryproducts and are therefore not limited to particular parts of fish.

Animal wastes for use in the present invention may include excretaproduced in livestock industries by livestock including cows, horses,hogs, and poultry, or excreta produced by other animals and humans.

Distillatory effluents for use in the present invention include wasteliquids produced while manufacturing distilled liquors such as shochuliquor, whiskey, brandy, and vodka.

Koji molds for use in the present invention include those that haveconventionally been used in the production of koji, and preferably,those belonging to genus Aspergillus or genus Monascus. As genusspergillus, Aspergillus orygae, Aspergillus sojae, Aspergillus Tamarii,Aspergillus Katsuobushi, Aspergillus Awamori Aspergillus niger, andAspergillus glancus, for example, may be used in the present invention.As genus Monascus, Monascus purpureus and Monascus Anka may be cited asexamples. The grain materials and fiber materials are used as they are.It is preferable to sterilize the mixture by steaming after mixing thecomponents.

The mixing ratio of the above-described grain materials, and/or fibermaterials, to at least one of industrial wastes selected from the groupconsisting of fish broth, fish viscera, animal wastes, and distillatoryeffluents is preferably from 1:0.5 to 1:2 by weight when measured withwater content. The typical water content for each of the components isas follows: about 15 wt % for grain materials, about 12 wt % for fibermaterials, about 80 to 90 wt % for fish viscera, and about 95 wt % forfish broth and animal waste. It is not desirable for the proportion ofthe former to be large, since insufficient koji growth may take place,while it is not desirable for the proportion of the latter tobe largesince the mixture will tend to rot.

In the present invention, the above-mentioned grain materials, and/orfiber materials, and at least one of industrial waste containing animalprotein for example the one selected from the group consisting of fishbroth, fish viscera, animal waste, and distillatory effluent are mixedwith one another with the mixing ratio described above. The watercontent of the mixture is preferably 45 wt % or less. The mixing may becarried out by various mixing methods. The above-mentioned koji mold isthen added to the resulting mixture. The preferred mixing ratio of thekoji mold is from 0.05 to 0.1 wt % with respect to the total weight ofthe mixture. With the mixing ratio of less than 0.05 wt %, thefermentation efficiency is decreased, tendency to rot is increased, andthe productivity is lowered. With mixing ratio greater than 0.1 wt %,the increasing cost for koji mold makes it less suitable for industrialwaste treatment.

The production method of the animal feed according to the presentinvention is characterized by fermenting a mixture of theabove-mentioned grain materials, and/or fiber materials, and one of fishbroth, fish viscera, animal wastes, and distillatory effluents, which isfollowed by the drying of the mixture and the adjustment of the watercontent of the final product. The fermentation, the drying, and thewater-content controlling may be carried out in one step or in aplurality of steps involving addition of further materials.

In the case of the method comprising one step, the above-mentioned grainmaterials and/or fiber materials are mixed with one of fish broth, fishviscera, animal wastes, and distillatory effluents, with the mixingratio described above. The koji mold is added to the resulting mixturein an amount within the range described above in terms of weight %. Thefermentation begins spontaneously. Heat is generated when thefermentation takes place. The mixture is dried by making use of the heatgenerated by the fermentation. The water content in the crude mixture ispreferably 45 wt % or less. The water content in the final product ispreferably 30 wt % or less, more preferably 20 wt % or less, and evenmore preferably 10 wt % or less. The water content greater than 30 wt %causes the total volume to increase, which makes storage andtransportation of the products difficult. This is also unfavorable sincea product with high water content has a reduced storage life and couldreadily rot.

During fermentation, it is preferred to control the temperature tofacilitate, or to suppress, fermentation. The preferred fermentationtemperature for koji mold is in the range of 30° C. to 50° C. Thetemperature is therefore controlled to this range. An economical andeffective way of doing this is to drive a current of air onto themixture by a fan, or the like. Also, depending on the humidity in thesystem, a current of hot air may be employed to facilitate the drying ofthe mixture. The air may be heated using, for example, a steam heater.

For the purpose of increasing the concentration of effective ingredientsin the final product, the animal feed according to the present inventionmay be produced by a method comprising a plurality of steps in whichfurther material is added and the fermentation, the drying and thewater-content adjustment are subsequently carried out. After this secondstep, controlling the water content is crucial. In general the activerange of water content for typical bacteria growth is 0.91-1.00 and thatfor typical yeast 0.88-1.00, while that for koji mold is 0.80-1.00.Therefore, the best way to exclusively promote the growth of the kojimold is by regulating the active range of water content to be in therange of 0.80-0.87. In such a case, the following steps must befollowed.

In a two-step method, when the water content of the mixture obtainedfrom the above-described one-step method is decreased from 45 wt % downto 35 wt % after the fermentation and drying, additional industrialwaste is mixed with the mixture such that the water content after mixingis from 40 to 45 wt %. This is followed by further fermentation anddrying to obtain a product with a water content of 30 wt % or less.

In a three-step method, when the water content of the mixture obtainedfrom the above-described two-step method is decreased to 35 wt % orless, further industrial waste is added to the mixture and mixed suchthat the water content after mixing is from 40 to 45 wt %. This isfollowed by a third fermentation and drying to obtain a product with awater content of 30 wt % or less.

Though the number of the steps in the method is not limited, too manysteps may result in insufficient fermentation. Therefore, the method maypreferably comprise at most three steps as described above.

Table 1 below shows the effectiveness of the present invention. As shownin the table, the cow waste and bran mixture processed according to thepresent invention is richer in crude protein with comparison to the meremixture of the same materials without processing.

TABLE 1 Comparison of crude protein and other ingredients (wt %) CrudeCrude Nitrogen-free Crude Crude Protein Fat Materials Fiber ash CowWaste 25.2 4 54.8 8 8 Bran 17.7 4.7 61.4 10.5 5.7 Cow Waste/Bran 19.54.5 59.7 9.8 6.3 Mixture Fermented Cow 23 4 49.5 14.5 9 Waste/BranMixture

The present invention will now be described in detail by explanatoryexamples, which are to be considered as illustrative, rather thanrestrictive.

EXAMPLE 1

200 kg of bran (14 wt % water content) were mixed with 100 kg of fishbroth effluent (95 wt % water content). The amount of water in thismixture was 123 kg and the water content of the mixture was 41 wt %. 300g of spores of aspergillus (0.1 wt % with respect to the total weight ofthe mixture) were added to the mixture. The mixture was thoroughlymixed. After sterilizing it by steaming, the crude mixture into whichkoji mold had been thoroughly mixed was placed in a fixed-type airconductive incubator.

With the growth of the mold, generation of heat started approximately 12hours after the mixing of the mold. A stream of air was driven onto themixture as necessary to hold the temperature in the optimum range of 30°C. to 50° C. The growth of the mold was then maximized 17 to 30 hoursafter fermentation was initiated and the temperature was increased to45° C. The fermentation continued further. Hot air heated by a steamheater was driven onto the mixture 33 hours after the initiation offermentation to dry the mixture further. As a result, 190 kg of animalfeed (i.e. fermentation product) of the present invention having a watercontent of 10 wt % were obtained 48 hours after the initiation offermentation.

EXAMPLE 2

200 kg of bran (14 wt % water content) were mixed with 100 kg of fishbroth effluent (95 wt % water content). 200 g of spores of aspergillus(0.06 wt %) were added to the mixture and mixed thoroughly. Aftersterilizing it by steaming, the crude mixture into which koji mold hadbeen thoroughly mixed was placed in a fixed-type air conductiveincubator.

As the mold grew, generation of heat was observed approximately 12 hoursafter the mixing of the mold. A stream of air was driven onto themixture sufficient to hold the temperature in the optimum range of 30°C. to 50° C. 36 hours after the initiation of fermentation when thewater content became 30 wt %, 50 kg of additional fish broth effluent(95 wt % water content) were added to make a mixture with the watercontent of 41 wt %. The growth of the mold was then maximized and thetemperature was increased to 48° C.

50 kg of additional fish broth effluent (95 wt % water content) wereadded after 60 hours when the water content became 32 wt % to make amixture with 44 wt % water content. A stream of hot air, passed througha steam heater, was driven onto the mixture to increase the dryingefficiency. As a result, 190 kg of animal feed (i.e. fermentationproduct) of the present invention having a water content of 10 wt % wereobtained 84 hours after the initiation of fermentation.

EXAMPLE 3

200 kg of bran (14 wt % water content) were mixed with 200 kg of fishviscera. 200 g of spores of aspergillus (0.05 wt %) were added to themixture. After sterilizing the mixture by steaming, the water content ofthe mixture was 45 wt %. The crude mixture into which koji mold had beenthoroughly mixed was placed in a fixed-type air conductive incubator.

With the growth of the mold, generation of heat was observedapproximately 12 hours after the admixture of the mold. A stream of airwas driven onto the mixture to sufficient to control the temperature inthe optimum range of 30° C. to 50° C. 24 hours after the initiation offermentation when the water content became 30 wt %, 100 kg of additionalfish viscera were added to the mixture. This made a mixture with 41 wt %water content. The growth of the mold was then maximized and thetemperature of the mixture was increased to 50° C.

48 hours after the mixing of the mold when the water content became 30wt %, 100 kg of further fish viscera were added to the mixture. Thismade a mixture with 41 wt % water content. As a result, 220 kg of animalfeed (i.e. fermentation product) of the present invention having a watercontent of 20 wt % were obtained 72 hours after the initiation offermentation.

EXAMPLE 4

200 kg of bran (14 wt % water content) were mixed with 150 kg of animalwaste (cows) (75 wt % water content). The mixture was sterilized bysteaming for 30 minutes. After sterilization, the mixture was cooled to45° C. and 200 g of spores of aspergillus (0.06 wt %) were added. Themixture was thoroughly mixed. The mixture had a water content of 40 wt%. The crude mixture into which koji mold had been thoroughly mixed wasplaced in a fixed-type air conductive incubator.

With the growth of the mold, generation of heat was observedapproximately 12 hours after the mixing of the mold, while the odor ofanimal waste disappeared. A stream of air was driven onto the mixture tohold the temperature in the optimum range of 30° C. to 50° C. 24 hoursafter the initiation of fermentation when the water content became 30 wt%, 50 kg of additional sterilized animal waste (75 wt % water content)were added to the mixture. This made a mixture with 35 wt % watercontent. The growth of the mold was then maximized and the temperatureof the mixture was increased to 48° C.

36 hours after the mixing of the mold when the water content became 30wt %, 50 kg of additional sterilized animal waste (75 wt % watercontent) were added to the mixture. This made a mixture with 35 wt %water content. A stream of hot air, passed through a steam heater, wasdriven onto the mixture to increase the drying efficiency. As a result,220 kg of animal feed (i.e. fermentation product) of the presentinvention having a water content of 10 wt % were obtained 60 hours afterthe initiation of fermentation.

Also, it was found that the animal feed of the present invention hadsignificantly facilitated digestion in the livestock animals fed withthe animal feed of the present invention.

EXAMPLE 5

1 ton of bran (14 wt % water content) were mixed with 500 liters ofdistillatory effluent (95 wt % water content). After sterilization, themixture was cooled to 40° C. and 1 kg of spores of aspergillus wereadded. The mixture was further cooled to 35° C. The mixture had thewater content of about 41 wt %. The crude mixture with which koji moldbad been thoroughly mixed was placed in a fixed-type air conductiveincubator. With the growth of the mold, generation of heat was observedapproximately 8 hours after the mixing of the mold. A stream of air wasdriven onto the mixture to hold the temperature in the optimum range. 24hours after the initiation of fermentation when the water content became35 wt %, 200 liters of additional distillatory effluent were added tothe mixture. This made a mixture with 43 wt % water content. The growthof the mold was then maximized and the temperature of the mixture wascontrolled to 40° C. As a result, 60 hours after the mixing of the mold,1 ton of animal feed (i.e. fermentation product) of the presentinvention having a water content of 30 wt % was obtained.

While there has been described what are at present considered to bepreferred embodiments of the present invention, it will be understoodthat various modifications may be made thereto, and it is intended thatthe appended claims cover all such modifications as fall within the truespirit and scope of the invention.

I claim:
 1. An animal feed comprising a grain material and/or a fibermaterial, an industrial waste containing protein of animal origin, kojimold and digestive enzymes produced thereby.
 2. An animal feed accordingto claim 1, wherein the industrial waste containing protein of animalorigin is an industrial waste selected from fish-broth effluents, fishviscera, and animal wastes.
 3. An animal feed according to claim 1 or 2,wherein the water content is 30 wt % or less.
 4. An animal feed producedby mixing a grain material and/or a fiber material with at least oneindustrial waste selected from fish-broth effluent, fish viscera, andanimal waste, to form a mixture, adding koji mold to the mixture tocause fermentation, and drying it to form the animal feed.
 5. The animalfeed according to claim 4, wherein the mixing ratio of the grainmaterial and/or the fiber material to the industrial waste is from 1:0.5to 1:2 by weight.
 6. The animal feed according to claim 4 or 5, whereinthe koji mold is added to the mixture in an amount in the range of 0.05wt % to 0.2 wt % with respect to the weight of the mixture.
 7. Theanimal feed according to claim 4 or 5, wherein the water content of theanimal feed after the fermentation and the drying is 30 wt % or less. 8.The animal feed according claim 6, wherein the water content of theanimal feed after the fermentation and the drying is 30 wt % or less. 9.A method for producing animal feed, the method comprising the steps of:mixing a grain material and/or a fiber material with at least oneindustrial waste selected from fish-broth effluent, fish viscera, andanimal waste, to form a mixture, wherein the water content of themixture is 45 wt % or less; adding koji mold to the mixture to causefermentation; and drying the mixture by utilizing heat generated by thefermentation caused by the koji mold.
 10. The method for producinganimal feed according to claim 9, wherein the water content of theanimal feed after the fermentation and the drying is 30 wt % or less.11. The method according to claim 9, wherein the drying step furthercomprises the step of mixing with the mixture an additional volume of atleast one industrial waste when the water content of the mixture is to35 wt % or less, to form a mixture having a water content in the rangeof 40 wt % to 45 wt %, the industrial waste being selected fromfish-broth effluents, fish viscera, and animal the mixture being allowedto continue with fermentation and drying to form an animal feed with awater content of 30 wt % or less.
 12. The method according to claim 9,wherein the drying step further comprises the step of mixing with themixture an additional volume of at least one industrial waste when thewater content of the mixture is reduced to 35 wt % or less, to form amixture having a water content in the range of 40 wt % to 45 wt %, theindustrial waste selected from fish-broth effluent, fish viscera, andanimal waste, the mixture being allowed to continue with fermentationand drying until the water content is reduced to 35 wt % or less, thenmixed with a further volume of at least one industrial waste selectedfrom fish broth effluent, fish viscera, and animal waste, to form amixture having a water content in the range of 40 wt % to 45 wt %, themixture being allowed to continue with fermentation and drying to formthe animal feed with a water content of 30 wt % or less.